Que- Which of the following operators can operate on a boolean variable? 1. && 2. == 3. ?: 4. +=
a. 3 & 2
b. 1 & 4
c. 1, 2 & 4
d. 1, 2 & 3
Answer- 1, 2 & 3
Que- What is true about protected constructor?
a. Protected constructor can be called directly
b. Protected constructor can only be called using super()
c. Protected constructor can be used outside package
d. protected constructor can be instantiated even if child is in a different package
Answer- Protected constructor can only be called using super()
Que- What is not the use of "this" keyword in Java?
a. Passing itself to another method
b. Calling another constructor in constructor chaining
c. Referring to the instance variable when local variable has the same name
d. Passing itself to method of the same class
Answer- Passing itself to method of the same class
Que- What would be the behaviour if one parameterized constructor is explicitly defined?
a. Compilation error
b. Compilation succeeds
c. Runtime error
d. Compilation succeeds but at the time of creating object using default constructor, it throws compilation error
Answer- Compilation succeeds but at the time of creating object using default constructor, it throws compilation error
Que- What would be behaviour if the constructor has a return type?
a. Compilation error
b. Runtime error
c. Compilation and runs successfully
d. Only String return type is allowed
Answer- Compilation error
Que- Which of the following has the highest memory requirement?
a. Heap
b. Stack
c. JVM
d. Class
Answer- JVM
Que- Where is a new object allocated memory?
a. Young space
b. Old space
c. Young or Old space depending on space availability
d. JVM
Answer- Young space
Que- Which of the following is a garbage collection technique?
a. Cleanup model
b. Mark and sweep model
c. Space management model
d. Sweep model
Answer- Mark and sweep model
Que- What is -Xms and -Xmx while starting jvm?
a. Initial; Maximum memory
b. Maximum; Initial memory
c. Maximum memory
d. Initial memory
Answer- Initial; Maximum memory
Que- Which exception is thrown when java is out of memory?
a. MemoryFullException
b. MemoryOutOfBoundsException
c. OutOfMemoryError
d. MemoryError
Answer- OutOfMemoryError
Que- How to get prints of shared object memory maps or heap memory maps for a given process?
a. jmap
b. memorymap
c. memorypath
d. jvmmap
Answer- jmap
Que- What happens to the thread when garbage collection kicks off?
a. The thread continues its operation
b. Garbage collection cannot happen until the thread is running
c. The thread is paused while garbage collection runs
d. The thread and garbage collection do not interfere with each other
Answer- The thread is paused while garbage collection runs
Que- Which of the below is not a Java Profiler?
a. JVM
b. JConsole
c. JProfiler
d. Eclipse Profiler
Answer- JVM
Que- Which of the below is not a memory leak solution?
a. Code changes
b. JVM parameter tuning
c. Process restart
d. GC parameter tuning
Answer- Process restart
Que- What is the process of defining two or more methods within same class that have same name but different parameters declaration?
a. method overloading
b. method overriding
c. method hiding
d. none of the mentioned
Answer- method overloading
Que- Which of these can be overloaded?
a. Methods
b. Constructors
c. All of the mentioned
d. None of the mentioned
Answer- All of the mentioned
Que- Which of these is correct about passing an argument by call-by-value process?
a. Copy of argument is made into the formal parameter of the subroutine
b. Reference to original argument is passed to formal parameter of the subroutine
c. Copy of argument is made into the formal parameter of the subroutine and changes made on parameters of subroutine have effect on original argument
d. Reference to original argument is passed to formal parameter of the subroutine and changes made on parameters of subroutine have effect on original argument
Answer- Copy of argument is made into the formal parameter of the subroutine
Que- What is the process of defining a method in terms of itself, that is a method that calls itself?
a. Polymorphism
b. Abstraction
c. Encapsulation
d. Recursion
Answer- Recursion
Que- Which of these access specifiers must be used for main() method?
a. private
b. public
c. protected
d. none of the mentioned
Answer- public
Que- Which of these is used to access a member of class before object of that class is created?
a. public
b. private
c. static
d. protected
Answer- static
Que- Which of these is used as a default for a member of a class if no access specifier is used for it?
a. private
b. public
c. public, within its own package
d. protected
Answer- private
Que- What is the process by which we can control what parts of a program can access the members of a class?
a. Polymorphism
b. Abstraction
c. Encapsulation
d. Recursion
Answer- Encapsulation
Que- Which of the following statements are incorrect?
a. public members of class can be accessed by any code in the program
b. private members of class can only be accessed by other members of the class
c. private members of class can be inherited by a subclass, and become protected members in subclass
d. protected members of a class can be inherited by a subclass, and become private members of the subclass
Answer- private members of class can be inherited by a subclass, and become protected members in subclass
Que- Which of these access specifier must be used for class so that it can be inherited by another subclass?
a. public
b. private
c. protected
d. none of the mentioned
Answer- public
Que- Which one of the following is not an access modifier?
a. Public
b. Private
c. Protected
d. Void
Answer- Void
Que- All the variables of class should be ideally declared as?
a. private
b. public
c. protected
d. default
Answer- private
Que- Which of the following modifier means a particular variable cannot be accessed within the package?
a. private
b. public
c. protected
d. default
Answer- private
Que- How can a protected modifier be accessed?
a. accessible only within the class
b. accessible only within package
c. accessible within package and outside the package but through inheritance only
d. accessible by all
Answer- accessible within package and outside the package but through inheritance only
Que- What happens if constructor of class A is made private?
a. Any class can instantiate objects of class A
b. Objects of class A can be instantiated only within the class where it is declared
c. Inherited class can instantiate objects of class A
d. classes within the same package as class A can instantiate objects of class A
Answer- Objects of class A can be instantiated only within the class where it is declared
Que- All the variables of interface should be?
a. default and final
b. default and static
c. public, static and final
d. protect, static and final
Answer- public, static and final
Que- What is true of final class?
a. Final class cause compilation failure
b. Final class cannot be instantiated
c. Final class cause runtime failure
d. Final class cannot be inherited
Answer- Final class cannot be inherited
Que- How many copies of static and class variables are created when 10 objects are created of a class?
a. 1, 10
b. 10, 10
c. 10, 1
d. 1, 1
Answer- 1, 10
Que- Can a class be declared with a protected modifier.
a.TRUE
b.FALSE
c.Nothing Can be Said
d.None of the mentioned
Answer-FALSE
Que- Which is the modifier when there is none mentioned explicitly?
a. protected
b. private
c. public
d. default
Answer- default
Que- Arrays in Java are implemented as?
a. class
b. object
c. variable
d. none of the mentioned
Answer- object
Que- Which of these keywords is used to prevent content of a variable from being modified?
a. final
b. last
c. constant
d. static
Answer- final
Que- Which of these cannot be declared static?
a. class
b. object
c. variable
d. method
Answer- object